Unexamined German Patent No. 195 03 821 describes an electromagnetically operated fuel injection valve having a metal base body of the valve designed in one or two parts without a nonmagnetic intermediate part. The base body includes the inlet connection, a magnetic internal pole (core) and a valve seat carrier. In addition, the base body is responsible for guiding an armature which operates a valve closing body that works together with a valve seat. In addition, the base body has a magnetic choke point which has a much smaller wall thickness than the wall thicknesses of the upstream core and the downstream valve seat carrier.
Furthermore, Unexamined German Patent No. 195 37 382 also describes an electromagnetically operated fuel injection valve having an internal core and an external magnet housing. The magnet housing is designed as a stepped housing, forming a coil space between the core and the magnet housing to accommodate a magnet coil. The coil space is sealed with a cover element above the magnet coil and with a nonmagnetic intermediate part below the magnet coil. Thus, two additional parts are needed in addition to the core and the magnet housing to close the magnetic circuit or to prevent a magnet short-circuit.